Module me.ahoo.cosid.core

Package me.ahoo.cosid.time

Class TimeBasedGenerator

java.lang.Object

me.ahoo.cosid.time.TimeBasedGenerator

All Implemented Interfaces:

AutoCloseable, IdGenerator, PartsIdGenerator

public final class TimeBasedGenerator
extends Object
implements IdGenerator, PartsIdGenerator, AutoCloseable

The time-based generator: Snowflake layouts and the 80-bit CosId alike (03-core-model.md §4). Reads the slot binding once per id and checks the slot window before publishing the new state (§4.1); issuing is a short critical section and never waits while holding it.

Its public constructors are the assembly entry CosIdRuntime uses (R2-core-03): they keep their signatures, and a new parameter comes only through a builder or a static factory, never as one more positional overload (api-freeze.md §4.2).

Constructor Summary

Constructors

Constructor	Description
TimeBasedGenerator(String name, Layout layout, SlotHandle slot, int nodeOffset, TimeSource time, ClockRegressionPolicy regression, GeneratorListener listener)	A time-based generator whose node is the slot plus an offset: the slotOffset of a leased machine (api-freeze.md §2.1.1), so its nodes lie in [nodeOffset, nodeOffset + 2^bits).
TimeBasedGenerator(String name, Layout layout, SlotHandle slot, TimeSource time, ClockRegressionPolicy regression, GeneratorListener listener)	A time-based generator.

Method Summary

Modifier and Type	Method	Description
void	close()	Moves the sequencer to its terminal state; no id is issued once this returns.
long	generate()	Issues the next id.
long	lastIssuedMillis()	The time of the last issued id.
Layout	layout()	The bit layout of the ids.
String	name()	The generator name.
IdParts	nextParts()	The parts of the next id; thread-safe, never the same parts twice.
int	node()	The node the ids of the current binding carry: the slot plus the node offset.
int	slot()	The slot of the current binding.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

TimeBasedGenerator

public TimeBasedGenerator(String name,
 Layout layout,
 SlotHandle slot,
 TimeSource time,
 ClockRegressionPolicy regression,
 GeneratorListener listener)

A time-based generator.

Parameters:

name - the generator name, for events and errors

layout - the id layout; its node bits must cover the slot bits

slot - the machine slot, shared by every time-based generator of a runtime (D18)

time - the time source

regression - the clock regression policy

listener - the event listener; a listener that throws is logged and never fails or loses an id

TimeBasedGenerator

public TimeBasedGenerator(String name,
 Layout layout,
 SlotHandle slot,
 int nodeOffset,
 TimeSource time,
 ClockRegressionPolicy regression,
 GeneratorListener listener)

A time-based generator whose node is the slot plus an offset: the slotOffset of a leased machine (api-freeze.md §2.1.1), so its nodes lie in [nodeOffset, nodeOffset + 2^bits).

Parameters:

name - the generator name, for events and errors

layout - the id layout; its node bits must cover nodeOffset plus the slots

slot - the machine slot

nodeOffset - added to the slot to give the node of the ids, not negative

time - the time source

regression - the clock regression policy

listener - the event listener; a listener that throws is logged and never fails or loses an id

Method Details

name

public String name()

The generator name.

Returns:

the name

generate

public long generate()

Issues the next id.

Specified by:

generate in interface IdGenerator

Returns:

the id

Throws:

IllegalStateException - if the layout is wider than 63 bits, or the generator is closed

TimeOverflowException - if the time no longer fits the time bits of the layout

ClockBackwardsException - if the clock went back further than the regression policy allows, or before the epoch

nextParts

public IdParts nextParts()

Description copied from interface: PartsIdGenerator

The parts of the next id; thread-safe, never the same parts twice.

Specified by:

nextParts in interface PartsIdGenerator

Returns:

the parts

layout

public Layout layout()

The bit layout of the ids.

Returns:

the layout

slot

public int slot()

The slot of the current binding.

Returns:

the slot

node

public int node()

The node the ids of the current binding carry: the slot plus the node offset.

Returns:

the node

lastIssuedMillis

public long lastIssuedMillis()

The time of the last issued id.

Returns:

milliseconds since the Unix epoch, 0 when none was issued; exact once close() returned

close

public void close()

Moves the sequencer to its terminal state; no id is issued once this returns.

Specified by:

close in interface AutoCloseable